As you know it is sometime difficult for Teams administrators to have a complete view of things to work with, especially by using the Teams administration portal.
Well, it is now possible to export data from list pages like users, Teams or Teams channel.
To do so connect to your Teams administration portal (https://admin.teams.microsoft.com/) and access one of the blade listing your company Teams environment – more or less all the Manage ones: Manage teams, Manage users, all blade under Teams devices.
Once there you will see a small Excel icon on the right side of the header bar
Once you click on it there will be a download link showing up at the top right of the portal
The link will be available for 24 hours, after that you will have to repeat the export.